I took a friend to the final Boston showing of Mark Morris’s Pepperland today. What I expected to be a classical tribute to The Beatles turned out to be a fascinating avant garde interpretation of several of their lesser-known songs. A colorful flat-footed ballet coupled with a theremin- and harpsichord-led ensemble culminated in a dazzling performance reminiscent of Primus mixed with Nijinsky-like choreography.

The Beatles have always been known for their psychedelic music. Pieces like Lucy in the Sky with Diamonds are widely known to be thinly-veiled references to drug culture. Morris’s performance, however, recreates the classic Beatles trippiness through an odd reinterpretation of their music, namely by replacing Harrison’s soulful guitar with a harpsichord, a largely adynamic instrument, as well as peppering dissonance and polyrhythm throughout the performance. What results is a familiar but strangely alien cover of Sgt Pepper’s Lonely Hearts Club Band, where songs are at once recognizable and jarringly modified. Those who have witnessed Primus’s transformation of Charlie and the Chocolate Factory might draw apt comparisons between the two productions, though thankfully for the uninitiated, Pepperland is far less metal and far more accessible to the general audience.

There are too many musical innovations in Pepperland to go through each one fully in detail, but several are worth mentioning in particular. The third song, the timeless “With a Little Help from my Friends”, takes the first stanza literally and reinterprets the song with a meandering piano bassline that introduces an uncomfortable dissonance:

What would you do if I sang out of tune?  
Would you stand up and walk out on me?  
Lend me your ears and I'll sing you a song  
I will try not to sing out of key...  

Ironically, in Iverson’s version of “A Little Help”, it is not the singer who is out of key, but the piano left-hand which is intentionally out of key. Not only that, but careful listening will reveal that the keyboardist and singer are actually out of key by a quarter-tone at times. This results in a rendition of the song which on the surface sounds familiar given the preserved melody, but with a darker undertone as the bassline weaves in and out of key cyclically.

As someone particularly interested in music that incorporates polyrhythm (Dream Theater, Dillinger Escape Plan, Meshuggah), I took extra joy in watching “When I’m Sixty-Four”. Woah. The piece starts with one dancer carrying another on his back to the front of the stage, and both slowly dance a trippy, flatfooted/jazzhandy number to what begins as a typical 4/4 meter. Over the next several minutes, the tempo increases as more and more dancers pile onto stage, repeating the same dance. Eventually it culminates in a schizophrenic group dance where every other dancer dances to a counts of four, five, or six. It is extremely difficult to keep track of, but also tremendously fun to try to count to the beat. One by one, dancers slowly exit the group and start clapping the rhythm for the remaining dancers, until there is only one left.

I’m not exactly well-versed in ballet in general, but this concept draws pretty obvious roots from Stravinsky’s Rite of Spring, especially “The Sacrificial Dance” in which a female character famously dances herself to death as a sacrifice on behalf of the rest of her tribe. Indeed, Pepperland’s dances also incorporate heavy-footed stomps and jumps that immediately recall Nijinsky’s contributions to progressive and modern dance. Furthermore, the Pepperland dancers are intentionally emotionless and unsmiling, but highly physical and spirited in body movement alone, adding to a feeling of disconnect that was also present in many of Nijinsky’s dances.

These were the two standout songs in the performance, but vigilant audience members will notice that Iverson really enjoys introducing dissonance through the use of the P4 chord. Western music theory labels P4 as a “consonant” chord in the likes of a fifth, a unison, and an octave, but adding a fourth on top of the bassline tends to have a somewhat chilling, alien quality to it. (As an aside, Koji Kondo really likes to use P4s in The Legend of Zelda, particularly in the scenes with Midna, to create a similar effect without being outright dissonant with a tritone.) The result is somewhat reminiscent of Messaiaen’s “Quartet for the End of Times” at certain points, giving it a detached and indescribably unsettling feel. Couple this effect with the use of a theremin, which produces a weepy unstable tone, and you have the makings of a scene in a UFO movie. About the Beatles.

But for all the quirkiness and oddities with Pepperland’s music, the performance is ultimately fun and comedic, if not a little exotic. The music is not so dissonant and strange as to put the audience off completely, but as its name suggests, the composer seems to pepper in subtle changes here and there to keep us on our toes. In the end it’s a respectable tribute to Sgt Pepper and successfully innovates on what is already a very innovative album in its own right, and interested listeners will undoubtedly find new subtleties in the music with each revisit.